City to expand gunfire tracking

Tools

When a gunshot rings out in San Francisco this year, there will be more than double the chance that ShotSpotter technology will pinpoint where the firearm was discharged.

ShotSpotter, which immediately alerts police to shootings through sound sensors that detect gunfire, currently covers 3.3 square miles in the Mission, Western Addition and Bayview areas. With a $1 million grant from the federal Department of Justice, police intend to put up another 4 square miles of sensors in areas such as Visitacion Valley.

The money would also go toward installing the hardware in patrol cars so officers can receive reports of gunfire as soon as shots are fired.

The expansion would represent a significant jump toward The City’s goal of covering the 15 to 20 square miles where the majority of San Francisco’s violent crime occurs.

Lt. Mikail Ali, who has supervised the technology since the it was first purchased with a total of $400,000 in city funds in March 2008, said it has provided police with an invaluable tool that not only helps officers arrive to a crime scene faster, but also provides a forensic tool for solving crimes.

When a sharp blast is detected, the ShotSpotter software determines if it is a gunshot, firecracker or something else. The information goes to a dispatcher who can also listen to the noise and determine if it was correctly classified. Police supervisors can also listen to the noise and reclassify the sound.

The ability of the system to differentiate between fireworks, car backfires, helicopter blades and actual gunshots, however, is far from perfect.

Ali showed The Examiner several that needed to be reclassified. And in July, for instance, the number of gunshots before, after and during Independence Day spiked dramatically, along with a large increase in firecrackers detected.

In addition, despite a 10 percent reduction in violent crime in 2009 — with 54 percent fewer homicides compared with 2008 — the number of gunshots detected has remained about the same.

“There’s no real correlation to gunfire events and a drop in crime,” Ali said. “We’re just not seeing it.”

Mayor Gavin Newsom recently praised the technology as another tool for San Francisco’s officers and said a whole new crop of the coffee can-shaped sensors will be placed on government buildings and private residences throughout The City soon.

One hurdle that remains is that officials have been asked to put out a competitive bid for the contract. ShotSpotter, which is the technology The City already has in place, is made by a Mountain View company and is considered a leader in the field. Other companies that produce competitive technology include Sentri, which monitors smaller areas with cameras and microphones, and the Boomerang system — a mobile device used by the military to track sniper fire.